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Periodic Acid–Schiff Stain
Periodic acid–Schiff (PAS) is a staining method used to detect polysaccharides (such as glycogen) and mucosubstances (such as glycoproteins, glycolipids and mucins) in tissues. The reaction of periodic acid oxidizes vicinal diols in these sugars, usually breaking up the bond between two adjacent carbons not involved in the glycosidic linkage or ring closure in the ring of monosaccharide units that are part of the long polysaccharides and creating a pair of aldehydes at the two free tips of each broken monosaccharide ring. The oxidation condition has to be sufficiently regulated so as to not further oxidize the aldehydes. These aldehydes then react with the Schiff reagent to give a purple-magenta color. A suitable basic stain is often used as a counterstain. • PAS diastase stain (PAS-D) is PAS stain used in combination with diastase, an enzyme that breaks down glycogen. • Alcian blue/periodic acid–Schiff (AB/PAS or AB-PAS) uses alcian blue before the PAS step. Uses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Signet Ring Cell Carcinoma Histopatholgy (2) PAS Stain
The stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical terms related to the stomach. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase of digestion, following the cephalic phase in which the sight and smell of food and the act of chewing are stimuli. In the stomach a chemical breakdown of food takes place by means of secreted digestive enzymes and gastric acid. It also plays a role in regulating gut microbiota, influencing digestion and overall health. The stomach is located between the esophagus and the small intestine. The pyloric sphincter controls the passage of partially digested food (chyme) from the stomach into the duodenum, the first and shortest part of the small intestine, where peristalsis takes over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolar Soft Part Sarcoma
Alveolar soft part sarcoma, abbreviated ASPS, is a very rare type of soft-tissue sarcoma, that grows slowly and whose cell of origin is unknown. ASPS arises mainly in children and young adults and can migrate (metastasize) into other parts of the body, typically the lungs and the brain. Typically, ASPS arises in muscles and deep soft tissue of the thigh or the leg (lower extremities), but can also appear in the upper extremities (hands, neck, and head). While ASPS is a soft tissue sarcoma, it can also spread and grow inside the bones. Etymology * The term alveolar comes from the microscopic pattern, visible during the analysis of slides of ASPS under the microscope in histopathology. The tumor cells seem to be arranged in the same pattern as the cells of the small air sacks (alveoli) in the lungs. However, this is just a structural similarity. ASPS was first described and characterized in 1952. * ASPS is a sarcoma, and that indicates that this cancer initially arises from tissue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paget's Disease Of The Breast
Paget's disease of the breast (also known as mammary Paget's disease) is a rare skin change at the nipple nearly always associated with underlying breast cancer. Paget's disease of the breast was first described by Sir James Paget in 1874. The condition is an uncommon disease accounting for 1 to 4% of all breast cancers cases. 92% to 100% of patients with Paget's disease of the breast have an underlying breast cancer. The condition in itself often appears innocuous, limited to a surface appearance and it is sometimes dismissed, although it is actually indicative of underlying breast cancer. Signs and symptoms Paget's disease of the breast can affect the nipple and areola: the nipple is typically affected first and then the skin changes spread to the areola. It is common for symptoms to wax and wane. Symptoms typically only affect one breast and may include: * ''Skin:'' The first symptom is usually an eczema-like rash. The skin of the nipple and areola may be red, itchy, or ting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenocarcinomas
Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ; AC) is a type of cancerous tumor that can occur in several parts of the body. It is defined as neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or both. Adenocarcinomas are part of the larger grouping of carcinomas, but are also sometimes called by more precise terms omitting the word, where these exist. Thus invasive ductal carcinoma, the most common form of breast cancer, is adenocarcinoma but does not use the term in its name—however, esophageal adenocarcinoma does to distinguish it from the other common type of esophageal cancer, esophageal squamous cell carcinoma. Several of the most common forms of cancer are adenocarcinomas, and the various sorts of adenocarcinoma vary greatly in all their aspects, so that few useful generalizations can be made about them. In the most specific usage, the glandular origin or traits are exocrine; endocrine gland tumors, such as a VIPoma, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycogen Storage Disease
A glycogen storage disease (GSD, also glycogenosis and dextrinosis) is a metabolic disorder caused by a deficiency of an enzyme or transport protein affecting glycogen synthesis, glycogen breakdown, or glycolysis, glucose breakdown, typically in muscles and/or liver cells. GSD has two classes of cause: genetic and environmental. Genetic GSD is caused by any Inborn errors of carbohydrate metabolism, inborn error of carbohydrate metabolism (genetically defective enzymes or transport proteins) involved in these processes. In livestock, environmental GSD is caused by Substance intoxication, intoxication with the alkaloid castanospermine. However, not every inborn error of carbohydrate metabolism has been assigned a GSD number, even if it is known to affect the muscles or liver. For example, phosphoglycerate kinase deficiency (gene PGK1) has a myopathic form. Also, Fanconi–Bickel syndrome, Fanconi-Bickel syndrome (gene SLC2A2) and Danon disease (gene LAMP2) were declassed as GSDs d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Lamina
The basal lamina is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. It is often incorrectly referred to as the basement membrane, though it does constitute a portion of the basement membrane. The basal lamina is visible only with the electron microscope, where it appears as an electron-dense layer that is 20–100 nm thick (with some exceptions that are thicker, such as basal lamina in lung Pulmonary alveolus, alveoli and renal glomeruli). Structure The layers of the basal lamina ("BL") and those of the basement membrane ("BM") are described below: Anchoring fibrils composed of Collagen, type lightsaber VII, alpha 1, type VII collagen extend from the basal lamina into the underlying reticular lamina and loop around collagen bundles. Although found beneath all basal laminae, they are especially numerous in stratified squamous cells of the skin. These layers should not be confused with the lamina propria, which is found outsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycocalyx
The glycocalyx (: glycocalyces or glycocalyxes), also known as the pericellular matrix and cell coat, is a layer of glycoproteins and glycolipids which surround the cell membranes of bacteria, epithelial cells, and other cells. Animal epithelial cells have a fuzz-like coating on the external surface of their plasma membranes. This viscous coating is the glycocalyx that consists of several carbohydrate moieties of membrane glycolipids and glycoproteins, which serve as backbone molecules for support. Generally, the carbohydrate portion of the glycolipids found on the surface of plasma membranes helps these molecules contribute to cell–cell recognition, communication, and intercellular adhesion. The glycocalyx is a type of identifier that the body uses to distinguish between its own healthy cells and transplanted tissues, diseased cells, or invading organisms. Included in the glycocalyx are cell-adhesion molecules that enable cells to adhere to each other and guide the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucus
Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both Serous fluid, serous and mucous cells. It is a viscous colloid containing inorganic ions, inorganic salts, antimicrobial enzymes (such as lysozymes), Antibody, immunoglobulins (especially Immunoglobulin A, IgA), and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus covers the Epithelium, epithelial cells that interact with outside environment, serves to protect the linings of the respiratory system, respiratory, Digestion#Digestive system, digestive, and Genitourinary system, urogenital systems, and structures in the Visual system, visual and auditory systems from pathogenic Fungus, fungi, bacteria and viruses. Most of the mucus in the body is produced in the gastrointestinal tract. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connective Tissue
Connective tissue is one of the four primary types of animal tissue, a group of cells that are similar in structure, along with epithelial tissue, muscle tissue, and nervous tissue. It develops mostly from the mesenchyme, derived from the mesoderm, the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord, are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leukocytes. The term "connective tissue" (in German, ) was introduced in 1830 by Johannes Peter Müller. The tissue was already recognized as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteoglycan
Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to which the glycosaminoglycan is joined through a tetrasaccharide bridge (e.g. chondroitin sulfate- GlcA- Gal-Gal- Xyl-PROTEIN). The Ser residue is generally in the sequence -Ser- Gly-X-Gly- (where X can be any amino acid residue but proline), although not every protein with this sequence has an attached glycosaminoglycan. The chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions due to the occurrence of sulfate and uronic acid groups. Proteoglycans occur in connective tissue. Types Proteoglycans are categorized by their relative size (large and small) and the nature of their glycosaminoglycan chains. Types include: Certain members are considered members of the "small leucine-rich pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoprotein
Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
